A 38-year-old woman is diagnosed with stage IB cervical cancer on cone biopsy. She is being prepared for treatment planning. Which investigation is most appropriate to assess the extent of local and distant spread before deciding between radical hysterectomy and chemoradiation?

Explanation

## Staging Investigation for Stage IB Cervical Cancer ### MRI Pelvis: Gold Standard for Local Staging **Key Point:** MRI pelvis with contrast is the investigation of choice for accurate assessment of local tumor extent, parametrial involvement, and vaginal/bladder/rectal invasion in cervical cancer—critical for treatment planning. **High-Yield:** MRI has superior soft-tissue contrast resolution compared to CT, allowing precise determination of: - Tumor size and volume - Parametrial invasion (T-stage refinement) - Vaginal involvement - Bladder/rectal wall invasion - Pelvic lymph node assessment This information directly influences the choice between radical hysterectomy (if disease is localized) versus chemoradiation (if parametrial or adjacent organ involvement). ### Staging Investigations in Cervical Cancer | Investigation | Purpose | Indication | Limitation | |---|---|---|---| | **MRI pelvis** | Local staging, parametrial involvement | All stage IB–IIA | Cost, availability | | **CT abdomen/pelvis** | Distant metastases, para-aortic nodes | Bulky disease, high-risk features | Inferior soft-tissue contrast | | **Chest X-ray** | Pulmonary metastases | Baseline; limited sensitivity | Misses small lesions | | **PET-CT** | Distant metastases, para-aortic nodes | Recurrent/advanced disease | Not standard for primary staging | **Clinical Pearl:** FIGO 2019 staging of cervical cancer is **clinical/imaging-based**, not surgical staging. MRI is the preferred imaging modality for accurate local staging that guides treatment decisions. **Mnemonic:** **MRI for LOCAL, CT for DISTANT** — MRI excels at parametrial and adjacent organ assessment; CT is better for detecting distant metastases and para-aortic nodes.